Abstract: A new detection configuration devised for the Scanning Electron Microscope (SEM), which allows the imaging of the surfaces of a specimen at atmospheric pressure. Such a detection configuration gives rise to a new microscope: the Atmospheric Scanning Electron Microscope (ASEM). In this configuration the detector means, such as a backscattered electron detector, is placed between the pressure limiting aperture and the electron column. The electron beam passes through the final aperture, reaches the sample under atmospheric conditions and the backscattered electrons (or other signals) are allowed to reach the detector. The new configuration makes it possible for specimens or materials to be viewed in an open room. Examination of materials, not only in their natural state but also in their natural position, is possible. This feature of the ASEM will be extremely useful in areas where sampling is impossible, expensive or critical for the test subject, e.g.